A question about thermodynamics

[ApogeeUK]

Hi Folks,

A new member here.

Please forgive me if this has been covered already but some time ago I was indulging in that most futile of pastimes, debating the moon hoax theory with a poster on You Tube and some informed input would be appreciated. The issue in question concerned this person's belief that evidence of hoaxery lay in the fact that the flags used by the Apollo astronauts managed to survive exposure to solar radiation. It was their contention that the material should have simply disintegrated instantly in that environment.

I was lectured (in that way that suggests a little knowledge can be dangerous) about heat being absorbed by an object when exposed to solar radiation. In the Earth's atmosphere this absorbed heat is transferred throughout it and also through the atmosphere by the contact made with the atmospheric gases around it. Without this atmosphere, there is no medium to transfer heat to, and there is a build up of heat in the object and based on the composition of that object (in this case a nylon material) it will break down.

My response was simply that over forty five years the combination of sun-rot and micro-meteor impact had most lilkely proved devastating but that I didn't believe the flags were incapable of surviving the limited time the moonwalkers were around to film and photograph them. They're actual condition now I believe is effectively unknown. Not being an expert in physics, much of my argument was indirect and to do with the fact that there was practically no scientific dissent with regards to the moonlandings reality and I'd certainly never heard any expert attempting to make the presumably obvious point that the flags should have disintegrated on live TV.

Now I'm wishing I'd been more informed about the science involved to argue the case properly.

Can anyone here help me clarify why this misguided know-it-all was in error?

Many thanks in advance 

[Glom]

"coz atmosphere" is a stock HB technique.

While it is true that heat gets less distributed in an atmosphere, it can distribute through conduction. Plus net heat absorption decreases as temperature rises so there is a regulation mechanism there.

Really, you need to get logical here. Demand he show his numbers rather than just handwaving.

[Allan F]

As an item in vacuum gets hotter, it will radiate more and more energy away as infrared. There will - no matter the material or the circumstances - be a point where the incoming and outgoing energy balances, and the temperature does not rise anymore. This depends also on the angle to the sun, the color of the surface and other factors.

[onebigmonkey]

Welcome to the board

As far as the current condition of the flags is concerned, there is a degree of debate as to whether the flags are still intact enough to cast a shadow but are effectively bleached rags, or whether they have disintegrated completely.

The ALSJ has covered the topic: http://www.hq.nasa.gov/alsj/ApolloFlags-Condition.html

As for the contention that they would have been a pile of dust before the missions ended, this is pure nonsense. The ascent module lift-off footage shows the flags, and images taken from the surface over the course of the missions shows that the flags were there throughout, as demonstrated by the changing length of their shadows that are consistent with sun's movement in the lunar sky and time and date specific shots of Earth.

[ApogeeUK]

That's great. Many thanks for the swift (and knowledgeable) replies.

[Jason Thompson]

Welcome to the board.

Without this atmosphere, there is no medium to transfer heat to, and there is a build up of heat in the object and based on the composition of that object (in this case a nylon material) it will break down.

Arguments like this just make me lose faith in humanity. I learned, in school, when I was a teenager, that heat is transferred by conduction, convection and radiation. This obnoxious know-all (and for 'all' read 'very little') has managed to completely fail to identify that third method of heat transfer, which is doubly odd because how else does he think heat reaches us from the Sun through the vacuum of space in the first place?

[Luke Pemberton]

Not being an expert in physics, much of my argument was indirect and to do with the fact that there was practically no scientific dissent with regards to the moonlandings reality and I'd certainly never heard any expert attempting to make the presumably obvious point that the flags should have disintegrated on live TV.

As OBM has pointed out, there is  a degree of debate over the condition of the flags, but concensus would suggest that UV degrades the flags considerably, but this would take many years.

[Abaddon]

LRO imaged the flags with shadows, so it seem they have retained their gross physical shape. I would expect substantial bleaching, though.

[raven]

Welcome to the board.

Without this atmosphere, there is no medium to transfer heat to, and there is a build up of heat in the object and based on the composition of that object (in this case a nylon material) it will break down.

Arguments like this just make me lose faith in humanity. I learned, in school, when I was a teenager, that heat is transferred by conduction, convection and radiation. This obnoxious know-all (and for 'all' read 'very little') has managed to completely fail to identify that third method of heat transfer, which is doubly odd because how else does he think heat reaches us from the Sun through the vacuum of space in the first place?

Or how it gets cold at night, for that matter.

[Zakalwe]

..... how else does he think heat reaches us from the Sun through the vacuum of space in the first place?

I've seen HBs claiming (with a straight face!) that heat cannot travel in a vacuum 

[Luke Pemberton]

I've seen HBs claiming (with a straight face!) that heat cannot travel in a vacuum 

I guess that means all other EM waves cannot travel through a vacuum either.   

I have to be honest, heat transfer is a tricky concept for a lot of students, and there are many misconceptions that develop over time. I honestly believe if an HB thinks that heat does not travel in a vacuum, then science is really not their strongest suit, and it is unlikely they will move beyond their experience without serious face-to-face intervention. I would suggest that something went horribly wrong during their secondary (high school) education and no amount of typing on a keyboard will change them.

[sts60]

I've seen HBs claiming (with a straight face!) that heat cannot travel in a vacuum 

I guess that means all other EM waves cannot travel through a vacuum either.

You would like the threads by solon over at Bad Astronomy/cosmoquest.  He insisted that transverse EM waves could not travel in a vacuum, only plane waves (which people kept pointing out were merely a representation of transverse waves from a distant object).  According to him, the only reason we see stars, planets, the Moon or even the Sun is because of "conversion" in the ionosphere.

Solon kept claiming that no image of x taken from y existed, or that some simple optical system had some sort of fancy grating, etc., and was quickly demonstrated to be wrong each time.  He had to mount his goal posts on jet-propelled Teflon skates on an ice field to try to outrun the fail, with the predictable result of contradicting himself in the same post pretty regularly.

He spent lots of time saying how he was just tracking down the facts Columbo-style, or needed just one more piece of random performance data, but he simply wouldn't stop and consider he might just be wrong.

[Luke Pemberton]

You would like the threads by solon over at Bad Astronomy/cosmoquest.

It's been so long I have forgotten my username and password, and can't remember the email address connected with the account. I'll take a look as a lurker though, even if for the sake of entertainment.

He insisted that transverse EM waves could not travel in a vacuum, only plane waves (which people kept pointing out were merely a representation of transverse waves from a distant object).

He needs to read Huygen's principle and understand the construct of waves and their physical interpretation. He can then dig into Fraunhofer and Fresnel, and follow that one up with Maxwell. Once he's done that, he might like to dig into some quantum mechanics, and then I'll talk to him about the physical interpretation of waves.

I just find these people so arrogant when they made such bold assumptions, yet have made no attempt to scholar themselves. They clearly just make it up. Ralph Rene was the same, and I can say this with confidence now I have hold of his Last Skeptic of Science.

According to him, the only reason we see stars, planets, the Moon or even the Sun is because of "conversion" in the ionosphere.

Interesting in the sense that what makes someone so deluded? Clearly he's read a little about the ionosphere and thinks its a magic boundary (well, it is in a way).

He had to mount his goal posts on jet-propelled Teflon skates on an ice field to try to outrun the fail, with the predictable result of contradicting himself in the same post pretty regularly.

Where can I buy such skis, as I am about to go holidaying in Scotland around a couple of the great Lochs?

He spent lots of time saying how he was just tracking down the facts Columbo-style, or needed just one more piece of random performance data, but he simply wouldn't stop and consider he might just be wrong.

Did he abandon threads with the phrase 'just one more question?'

[frenat]

You would like the threads by solon over at Bad Astronomy/cosmoquest.

It's been so long I have forgotten my username and password, and can't remember the email address connected with the account.

That's why I use Lastpass to save all my passwords.  I've been using it for a few years now and occasionally come across sites that I signed up for before and forgot about but still have access to because Lastpass kept all the info.